Balance-escapement



(No Model.)

C. E. EMERY.

. BALANCE BSGAPBMBNT.

No. 443,165. Patented Dec. 23, 1890.

v UNITED 'STATES PATENT Orricn.

CHARLES E. EMERY, OF BROOKLYN, NEV YORK.

BALANCE-ESCAPEM ENT.

SPECIFICATION forming part of Letters Patent No. 443,165, dated December23, 1890.

Application filed January 20, 1890. Serial No. 337,413. (No model.)

.To @ZZ whom it may concern:

Be it known that I, CHARLES E. EMERY, of Brooklyn, Kings county, NewYork, (office, New York city,) have invented a new and Improved LeverOhronometer-Escapement; and I do hereby declare that the following is afull, clear, and exact description thereof7 reference being ,had to theaccompanying drawings, making part of this specification.

In chronometers of special design the locking-stone has heretofore beenmounted on one arm of a lever or anchor and a second stone set angularlyin the other end of the anchor, so as to receive on its inclined surfacea tooth of the escape-Wheelimmediately after the impulse, and therebybring the anchor and locking-stone back into position, thereby obviatingthe necessity of a spring for that purpose. It has been suggested, also,that a locking-anchor can be operated by a forked lever and pin the sameas in ordinary lever Watches. The anchor in such case would be like thatof the ordinary anchor-escapement Without the impulse-faces. One stoneor pallet, which we will call the releasingpallet, releasing theescape-Wheel for the impulse and the other stone or pallet, which wewill call the transfer-pallet, stopping the escape-wheel after theimpulse and simply acting to transfer the lock with a very small drop tothe releasing-pallet. Evidently the motion required for suc-h aleverWould be very small, as the pallets would need to move only throughthe locking-angles. Consequently the lever-operating pin would run outof the fork immediately after the release and the lever be only held inplace during theimpulse by the banking-pin on one side and the safe--ty-pin on the other, requiring a very nice adjustment of the latter andmaking it im possible to determine with certainty the friction caused bythe lever during the impulse as it might at times be left With thesafety-pin againstthe roller, so as to cause friction and at others restagainst a banking -pin; but there is nothing in the apparatus itself topositively produce the latter condition, and an objectionablespring-catch or other device would be required to secure itWithcertainty. This difliculty may be overcome by making thelever travelthrough a long arc While engaged with the fork; but in such case,evidently, the transfer-pallet would necessarily move back through thisarc with one of the teeth of the escape-Wheel resting upon its movingsurface, causing friction, as in the Graham dead-beat escapement forclocks. It has been attempted to palliate this difficulty by making thearm carrying the transfer-pallet shorter than the other; butthis remedymakes it impossible with the ordinary construction to secure for bothpallets the proper draw to hold the lever against the banking-pins. yThese various difficulties undoubtedly explain Why such an escapement isnot in general use. Keeping in mind the arrangement of an ordinarydetached lever-escapement and distinguishing the locking-pallet on thehook end as the inner7 locking-pallet and the other as the outerlocking-pallet, it will be seen that With such an arrangement therelease must be made by the outer locking-pallet and the transfer madefrom the inner locking-pallet.

This invention relates to an improvement whereby thel release iseffected by the inner locking-pallet, (or hook end of the anchor,) andthe transfer tothe same made from the outer locking-pallet, and meansare provided whereby the lever during impulse is moved in a contrarydirection fromwhat itwould be With the ordinary arrangement ofafleverescapement. The effect of this improvement is that the properAdraw or leverage equivalent to draw can be secured at both ends of theanchor When the arms are of unequal length, and the lever can be keptunder the control of the fork at all times When it is not held inposition by the pressure of atooth of the escape-Wheel on one or theother of the locking-pallets. Vith this improvement all the advantagesare gained of both the lever .and chronometer escapements Without thedefects of either. For instance, the impulse instead of being receivedon the inclined surfaces of the pallets, as in the lever escapement, isimparted directly by a tooth of the escape-Wheel upon an impulse pin orstone in a roller on the balance-staff, the same ask in the chronometerand' duplex escapements,

While the fork prevents the balance-Wheel.

from making more than two full revolutions,

the same as in a lever eseapement, so that the train cannot run7 or maketwo beatsin the proper' time for one, as is possible with thechronometer and duplex escapements. The result is secured without thefriction caused by the pressure of atooth of the escape-wheel on thebalance-statt incident to the duplex escapement, and the delicateslip-spring necessarilyemployed in the chronometereseapement to permitthe return of the unlocking cam, as well as the spring generally used tosecure the retraction of the locking-stone, is dispensed with.

In the dra\vings,Figu1e l is a plan view ofthe principal parts of theimproved escapement. Fig. 2 is a side view of the same. Fig. 3 is a planview of an attached anchor with locking-pallets, and Fig. 4 is avertical elevation of same.

A is the escape-wheel, of which a fragment only -is shown in Fig. l. ais the statt' ol the same. It is to be understood that this wheelreceives rotary motion from a train (not shown) through a pinion Z, Fig.il, or in any customary way.

Bis a view of the greater partof the bal ance-wheel, `(shown only indotted lines in Fig. 1,) and l) the statt of the same.

C represents Vin general the lever provided with arms C and C andeountenbalance C3. The staff of the lever is designated c. It is plantedoutside the greatest diameters of the escape-wheel and balance, therebymaking it possible to pivot it in the main plates.

The locking-pallets are designa-ted d and d', clbeing the outerlocking-pallet and acting as the transfer-pallet in this arrangement,and d being the inner lockingpallet and the releasing-pallet in thisarrangement.

D and D represent, respectively, the lower and upper plates of thewatch, each illustrated double in this particular case.

The jaws ot the fork are designated f and f. It will be observed that inthis arrangement the opening of the fork is in the direction of thestaff c of the lever instead of away from it, as in theordinaryconstruction. The jaws f and f of the fork are connected withthe lever by two curved portions e e', forming a yoke, although,evidently, one of these may be dispensed with, it desired. In thearrangement shown the lever .is continued beyond the 'fork by anextension g, which comes in contact, as the lever moves in eitherdirection, with the banking-pins 7L 7L. Secured to the extension g is asafety-piece I. (Shown Vdetached in plan and elevation below theleverand corresponding to a safety-pin.) The wedge-shaped point'z'of thepiecel passes iirst one side and then the other of a safetyroller J,crossing mid-position through a notch j in the same.

The lever-operating pin is designated k. Its outer half is cut away, asshown, and the pin mounted in a roller or crank-arm K, secured to thebalance-staff; but, if desired, such pin may be secured in the arm otthe balance. 'lhe impulse pin or stone is designated on, and may besecured in a separate roller, but is shown as securedin the arm L of thebalance-wheel. (Illustrated by dotted lines.)

The operation is as follows: The bottom ot' the eseape-wheelA tends tomove toward the left by its connection with the train; but in theposition shown motion is prevented by the tooth t engaging with thetranstenpallet (l. From thelposition of the parts it willbe seen thatthe top of the balance-wheel 13 has made its full movement from right toleft and is now returning, so that the lever-oper ating pin 7U' hasentered the fork from let't to right. As motion continues, thelever-operating pin 7o will carry the fork as drawn down, so that in duetime the transfer-pallet CZ will release the tooth but before .therelease actually takes place releasing-pallet d will have moved nearlyto the position (Z2, so that when the transfer-pallet (t actuallyunlocks the tooth t the escape-wheel will move slightly forward andtooth t* drop upon releasingpallet cl2, and be looked thereby in theposition shown by the dotted lines. As the top ot the balance-wheel Bcontinues its motion from left to right, the lever-operating pin 7u willrun out of the fork past the jaw j", when the center ot the lever willbe substantially in the position ol' the dotted line cn, and the balancebe completely detached from the escapement until returned by thehairspring. (Supposed to be attached to the statt Z), but not shown.) Onthe return movement (top ofbalance-wheel moving from right to left) thelever-operating pin 7o' `will again e11- gage with the fork, the center'of carried up slightly until the releasing-palt let d unlocks tooth t,when the tooth t of the escape-wheel, which has been held previously inthe position ot' the dotted lines, will fall upon impulse-pin mf, whichwill then be at or near the position m and keepin contact with it,thereby impulsing the balancewlleel until the tooth t" slips oft' thepin m, when the latter is in the position m2. rlhe tooth will then dropa shortdistance upon the transfer-pallet (Z, thus locking the train.rlhe top ot' the balance will then continue its motion from right toleft detached from the escapcment and return to the position shown andthe operation be repeated. The lever is held against a banking-pin oneach side when the balancewheel is detached from the escapement byleverage due to the position of the loclting surfaces ol the pallets (lCZ in relation to the center c of the lever, producing the same resultas the draw given the pallets ot a common anchor escapcment. Using theletters designating the pallets and staves as referring geometrieally tothe centers of same, it will he observed that the line (Zo is tangent tothe radius ad, passing through the point ot the tooth t. This tangentdo, as will `be seen, 'passes above the center c ot the lever,

so that the pressure of the tooth f upon the the lever be A IOO IIO

pallet d tends to carry the lever G up with the leverage co and therebyhold it against the banking-pin h. So, also, when releasingpallet d isin the position d2, the tangent at that point lies in the direction cl2p to the left of the center c of the lever a distance op', and the leverC is held against the banking-pin h by a leverage op. This result issecured even when the locking-faces are in radial lines from the centera of the escape-Wheel. The line d p2 will correspond with the tangentdgp when releasing-pallet moves to'position cl2, and the proper angle ofthe locking-faces of d and cl to give the leverage stated may be securedby forming the same with tools moving relatively around the point q,where the line d p2 intersects the tangent do.

Fig. 3, from a different pointof view, represents the pallets d and d',formed on a separate piece of metal E. The locking-surfaces may beformed on a circular piece of metal in the lathe by an outside cnt onthe circle r r, and an inside cut on the circles s. A hole c1 being alsoformed concentric with the center q, a cup-shaped piece maybe cut olfthe stock, the anchor formed by milling, then hardened, then mounted ona mandrel engaging with hole q, and the locking-surfaces of the pallets(Z CZ' polished with asmall rapidlyrevolving lap or stone acting, whileanchor is also revolved, on center q. rl`he anchorE can then be mountedon the staff c, as shown in Fig. 4f.

In Figs. 1 and 2 the pallets are shown as made of separate bits of stoneor metal socketed in the lever. Evidently these may be set from a centerr1 even when their faces are flat, as it will be a simple way of makingsuch faces radial from the center of the escapewheel, or such faces maybe formed or polished from the center q, so as to be arcs of circles, asin Fig. 3.

Evidently the pressure on pallet d with the leverage co' tends to holdthe lever against banking-pin 7L the same as would an angle of drawcd0-that is, the same as if the center c were located in the line do ofthe tangent-and the locking-face of the pallet d revolved from left toright through an angle equal to the angle edo. The angle imparted to thelocking-faces to hold the lever against the banking-pins is knowntechnically as draw and the equivalent result produced by the leveragedescribed, whether or not combined with draw, as above, may be calledeective draw. Similarly the leverage in relation to pallet d is the sameas an angle of draw ed p2 or c6121), so when the tendency to lie againstthe banking-pins produced by.

leverage is too little or too great the angles of the locking-faces ofpallets rl and d may be slightly changed, so that in combination withthe angles between the tangents and center of lever abovereferred togive the desired angle of effectivedraw. The leverage and draw, whichcombined make the effective draw, may be modified on the principlesabove expressed when the surfaces are circular or struck from acenter.For instance, if 'the locking-faces of the pallets be concentric with acenter to the right of the intersection q inthe direction of the centera of the escape-wheel, the effective vdraw will be reduced on pallet d',(becoming zero if carried to the line ccl,) and will increase theeffective draw on pallet d. Similarly, if the center be carried outsideof q away from a, the draw on pallet cl will be decreased and that onpallet d increased. In general, the proper position .of the center fromwhich the pallets are to be struck is at the intersection of lines drawnat right angles to the locking-faces when set at the desired angle ofdraw. This principle may be applied to secure circular lockingfaces froma common center on the anchor of an ordinary lever escapement. Byturning the roller K (of which a separate View is shown at the right) onthe staff b, the leveroperating pin 7c may be adjusted at such angle asto release the escape-wheel-when the impulse-pin m has sufficientlymoved Within the path of the points of the teeth of the escape` wheel tobe sure of its receiving Without fail the point of the tooth t3 when itdrops upon the pin to give the impulse.

The relative lengths of the arms of the lever C and the distance ofthelever-operating pin k from the center b of the balance-wheel( may beso adj usted in relation to each other that the lever-operating pin lewill be between the parallel sides of the jaws f f of the forkthroughout the whole impulse, thus preventing the safety-point t fromfalling against the roller J and producing friction during such impulse.In the particular eseapement laid down the lever-operating pin 7.",moves out from between the parallel sides of the jaws ff when theimpulsing-pin m is in the position shown or a little before thecompletion of the impulse; but in moving through the small angle from mto on? the lever-operating pin 7c does not become disengaged'from theinclined edge of the jaw f of the fork, and therefore the safety-pointt' is still held away from the roller J. With different proportions thelever-operating pin 7e maybe kept between the parallel portions of thejaws of the fork throughout the entire impulse, if thought desirable,particularly lfor fine watches, in which the angle of impulse would beless than that shown. It will be observed that if the pin k engaged witha forkopening away from the staff-c of the lever it would be necessaryto release the tooth of the escape-wheel to give the impulse by an outerpallet on a long arm and to transfer from a hook or inner pallet onashort arm, and whilel it might be possible to obtain the properleverage corresponding to draw on the long arm it would be impossible todo so for the short one, as can be seen by supposing the locking-facesandescape -wheel as drawn reversed in direction, so that the bottom ofthe latter would move from left to right, the le- IOO IIO

ver remaining as it is drawn. In such case, evidently, the tendencywould be for the tooth t, in contact with a reversed or inner surface atd, to throw the lever away from banking pin h and to cause thesafety-pin t' tobear upon safety-roller J,- making the arrangementimpracticable. In the arrangement shown, where the release takes placefrom the hook or inner pallet, the angles of draw canbe secured withoutdifliculty, and to make this plan operative it is necessary that theanchor be moved in the opposite direction from what it would be with theordinary arrangement of pin and fork-that is, the operating-pin must bethrown on the other side of the bal ance-statt and operated inconnection with an inside fork, or one of which the opening pointstoward the statt ot the lever. Any motion, however, which will throw theanchor in the opposite direction to that in which it would be moved inan ordinary leverescapement will answer the purpose. For in stance, ifthe ordinary arrangement of fork and pin were used on an intermediateshaft operated by gearing from the balance-statt the necessary motion otthe lever in a direction opposite that produced in the ordinaryarrangement would be secured.

Evidently the lever may be carried below the roller J, be curved aroundone side of statt b, brought. back to receive a safety-pin substantiallyin the position of the point t', and then run out and be bent upward andbackward, with the end in the form ol a fork to engage with the pin 7awithout altering the general arrangement or operation of all the parts.

That I claim as my invention, and desire to secure by Letters Patent,is-

1. In the construction of alever chronomet'er-escapement in which thelocking-pallets are spaced the same or a little greater distance apartthan the included teeth of the escape-wheel, a lever provided with atransfer-pallet near the fulcrum, a releasing-pallet at a greaterdistance from the iulcrum, and a fork opening toward the fulcrum, incombination with an escape-wheel and with a balance-wheel provided withcustomary means for operating the lever and receiving the impulse, allarranged and operating substantially as and for the purposes specified.

2. In the construction ot' a lever' chronometer-escapemeut, atransfeipallet, and a hook or inner pallet operating to release theescapewheel to impulse the balance-wheel, in com` bin-ation with suchescapewheel and with a balance-wheel provided with custo mary means toreceive the impulse and customary means for operating the lever in theproper direction to secure thc release at the proper time to produce theimpulse, substantially as and for the purposes specied.

3. In the construction of a lever chronomet'er-escapement, incombination with the torli f f opening toward the lever-statt and thelever-operating pin k, an impulse-pin mi, arranged relatively on theopposite side of the center ot' stati ZJ, substantially as and for thepurposes specitled.

4. In the construction of a leverchronomcter-escapement, in combinationwith a fork f f opening' toward the lever-stat`r`, a safetypoint z', ope1ating in connection with a safetyroller J substantially as and for thepurposes specified.

5. In the construction ot escapements, in combination with abalance-wheel, an escapewheel andan anchor, and customary means foroperating the anchor from the balance, outer and inner pallets withlocking-faces formed on aros ot circles from a common center eccentricwith that of the anehonstatl:` to facilitate construction and securecorrectad justment, substantially as and for the purposes specified.

G. In a lever chronometer-escapement, in combination with anescape-wheel and a balance-wheel provided with customary means foroperating a lever and receiving the im pulse, and necessarybanking-pins, a lever provided with locking-pallets set in substantiallyradial lines 'from the center of the escape-wheel and so arranged inrelation to the fulcrum ot' the lever that the force of the traintransmitted through the escape-wheel will tend to hold the leveragainstthe bankingpins, substantially as and for the purposes specified.

7. In the construction ot' a lever chronometer-escapement, an anchorwith circular locking-faces provided with a hole or equivalent at q forcentering it concentric with the locking-faces during construction, andwith a hole or equivalent means ot attachment to a statt' c, located inrelation to the pallets so as to secure etective draw, substantially asand for the purposes herein specified.

8. In the-construction of a lever escapeinent, in combination with anescapeavheel, a l'lalance-wheel and customary connecting parts tooperate a lever and receive the impulse,` and suitable bankingpins forsuch lcver, a level' provided with looking-pallets at unequal distancesfrom the lever-staff and with the statt arranged outside a tangent drawnfrom the point of contact of the outer locking-pallet with a tooth ofthe escapewheel and inside a tangent drawn from t-he point of contact ofthe inner locking-pallct with a tooth of the escape-wheel, whereby thepressure upon the locking-faces will tend to hold the lever against thebanking-pins by leverage, substantially as and for the purposesspecitled.

CITAS. E. EMERY.

Witnesses:

Aleones C. PENNELL, EUGENE J. REILLY.

IIO

